[doc30]

Since the father is a doctor, he could easily immigrate tot he U.S., increase his salary and avoid paying "child support" to his adult child. He would be outside the jurisdiction of the Canadian family courts.

[GMMAC]

"... He would be outside the jurisdiction of the Canadian family courts."

Unfortunately no - many U.S. jurisdictions (not certain how many but most likely a majority) have reciprocal arrangements with Canada when it comes to child and spousal support Orders.

Actually, in some respects, things are considerably worse for fathers in some parts of the U.S.
As example, in Kanuckistan, it's still fairly rare to see fathers jailed for noncompliance with such Orders.